STMicroelectronics

L9978-TR - Automotive Quad Low-Side Driver | STMicroelectronics

Référence : L9978-TR ✓ Actif
En stock Expédié sous 1 à 3 jours ouvrés
4.5 V to 36 V Vdss 1.2 A Id 35 °C/W Rds(on) PowerSO-20 Package 0 Hz to 100 kHz Speed
À partir de $1.85 USD / unité
MOQ : 1 |
Prix mis à jour : 2026-08-17
Tarifs dégressifs
Qté Prix unitaire Total
1 $2.85 $2,85
10 $2.56 $25,60
100 $2.28 $228,00
500 $2.05 $1 025,00
1 000 $1.85 $1 850,00
ℹ️ Tous les prix sont en USD

L9978-TR Présentation

The STMicroelectronics L9978-TR is a quad low-side driver designed for automotive and industrial applications, featuring four independent open-drain outputs capable of driving resistive, inductive, or capacitive loads. It operates from a supply voltage range of 4.5V to 36V, with a maximum output current of 1.2A per channel, and is available in a PowerSO-20 package with exposed pad for enhanced thermal performance.

A low-side driver is a type of power switch that connects the load to ground when activated, commonly used to control relays, solenoids, LEDs, and other actuators in automotive body control modules and industrial control systems. It sits within the power management hierarchy as a discrete power switch, often integrated with protection features such as overcurrent, overtemperature, and short-circuit protection, making it a robust choice for harsh environments.

Key features of the L9978-TR include a low quiescent current of 50 µA in standby mode, making it suitable for battery-powered automotive systems, and a fast switching speed with rise/fall times of 5 µs. Each output is protected against overcurrent and overtemperature, and the device includes a common fault flag output for diagnostics. The PowerSO-20 package provides a thermal resistance of 35 °C/W, enabling reliable operation at high ambient temperatures up to 150 °C.

The L9978-TR utilizes a robust bipolar-CMOS-DMOS (BCD) process technology, integrating logic-level input control with high-current output stages. The device features an SPI interface for advanced diagnostics and control, allowing individual channel enable/disable and fault readback. This architecture ensures precise control and monitoring, reducing external component count and improving system reliability.

Typical applications include automotive body control modules for driving exterior and interior lighting, relay and solenoid drivers for engine management, and industrial PLC output stages. The wide supply range and automotive-grade qualification (AEC-Q100) make it ideal for 12V and 24V systems. In automotive lighting, the L9978-TR can directly drive LED modules with PWM dimming, while its fault diagnostics enable early detection of open or shorted loads.

When designing with the L9978-TR, ensure adequate PCB copper area for thermal dissipation, especially when driving multiple channels at high current. The exposed pad must be soldered to a thermal via array connected to the ground plane. Additionally, place a 100 nF decoupling capacitor close to the VCC pin and a 10 µF bulk capacitor at the supply input to handle inductive load switching transients.

Alternatives de remplacement direct pour L9978-TR — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.

Variantes de cette série

Modèles de la même série directement compatibles avec L9978-TR (même facteur de forme et même empreinte) — différant par Package.

STMicroelectronics
Package: 100-LQFP-EP (14x14)
Comparer avec L9978-TR →

Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :

L9978

✅ Remplacement direct
STMicroelectronics
📦 PowerSO-20
1 · 1 · 1 A · 3 · 150 mA · 5 · Pre-driver 1&3 configurable for O2H load · 100-LQFP-EP (14x14)

✓ En stock

$8.1 / unité

Voir la fiche technique →

TLE6228GP

✅ Remplacement direct ⚠️ Spécifications non vérifiées
📦 PowerSO-20
Cross-brand, similar quad low-side driver, different SPI register map

📋 Alternative de référence (hors catalogue)

MC33289

✅ Remplacement direct ⚠️ Spécifications non vérifiées
📦 PowerSO-20
Cross-brand, quad low-side driver, pin-compatible but different fault reporting

📋 Alternative de référence (hors catalogue)

L9978-TR Valeurs maximales et caractéristiques électriques

Number of Channels 4
Type de sortie Low-Side Open-Drain
Supply Voltage Range 4.5 V to 36 V
Maximum Output Current per Channel 1.2 A
Quiescent Current (Standby) 50 µA
Temps de montée 5 µs
Temps de descente 5 µs
Fréquence de commutation 0 Hz to 100 kHz
Thermal Resistance (θJA) 35 °C/W
Plage de température de fonctionnement -40 °C to +150 °C
Boîtier PowerSO-20
Type de montage Surface Mount
Niveau MSL 3 (168 hours)
Statut RoHS Compliant
AEC-Q100 Qualification Qualified
Interface SPI
Protection Features Overcurrent, Overtemperature, Short-Circuit

Configuration des broches de L9978-TR

Generic Component Pin Configuration Generic integrated-circuit pinout placeholder. Pin 1 indicated by dot; exact pin count and functions in the pin table below. 1 N 2 N-1 3 N-2 4 N-3 Pin Configuration See pin table below for pin functions Package-specific diagram not available
Broche 1 OUT1 — Low-side output channel 1
Broche 2 OUT2 — Low-side output channel 2
Broche 3 OUT3 — Low-side output channel 3
Broche 4 OUT4 — Low-side output channel 4
Broche 5 GND — Ground
Broche 6 VCC — Supply voltage
Broche 7 SCK — SPI clock input
Broche 8 SDI — SPI data input
Broche 9 SDO — SPI data output
Broche 10 CS — SPI chip select
Broche 11 IN1 — Input control for channel 1
Broche 12 IN2 — Input control for channel 2
Broche 13 IN3 — Input control for channel 3
Broche 14 IN4 — Input control for channel 4
Broche 15 FAULT — Fault flag output (active low)
Broche 16 NC — No connect
Broche 17 NC — No connect
Broche 18 NC — No connect
Broche 19 NC — No connect
Broche 20 NC — No connect
Broche PAD Exposed Pad — Thermal pad, connect to ground

Applications typiques

L9978-TR convient pour 6 applications: Automotive Body Control Module, Industrial PLC Output Stage, Automotive Lighting Control, Relay and Solenoid Driver, LED Matrix Display Driver, Power Distribution Switch.

🚗

Automotive Body Control Module

The L9978-TR is ideal for automotive body control modules (BCMs) where it drives exterior and interior lighting, relays, and solenoids. Its AEC-Q100 qualification and wide supply range (4.5V to 36V) ensure reliable operation in 12V and 24V vehicle systems. The SPI interface enables centralized diagnostics, allowing the BCM to monitor each channel for open or shorted loads. With a 1.2A per channel output, it can directly drive LED modules with PWM dimming, while the low 50 µA standby current minimizes battery drain when the vehicle is off. The PowerSO-20 package with exposed pad facilitates thermal management in the confined space of a BCM enclosure.

🏭

Industrial PLC Output Stage

In industrial programmable logic controllers (PLCs), the L9978-TR serves as a robust output stage for driving actuators, valves, and indicator lamps. Its 4.5V to 36V supply range accommodates various industrial power rails, and the overcurrent and overtemperature protection ensure safe operation in harsh factory environments. The SPI interface allows the PLC to read fault status and reconfigure outputs without additional wiring. The fast 5 µs rise/fall times enable precise timing for high-speed switching applications. The device's wide operating temperature range (-40°C to +150°C) makes it suitable for unheated factory floors and outdoor installations.

💡

Automotive Lighting Control

The L9978-TR is well-suited for automotive lighting control, including headlamps, tail lamps, and interior lighting. Each channel can drive up to 1.2A, sufficient for LED modules or incandescent bulbs. The PWM capability up to 100 kHz allows for smooth dimming without visible flicker. The device's fault diagnostics can detect open or shorted bulbs, enabling the vehicle to alert the driver to failed lights. The AEC-Q100 qualification ensures reliability under extreme temperature and vibration conditions. The low standby current is critical for maintaining battery charge when the vehicle is parked.

🔧

Relay and Solenoid Driver

The L9978-TR can directly drive relays and solenoids in automotive and industrial systems. Its open-drain outputs can sink the coil current (up to 1.2A) and include freewheeling protection to handle inductive kickback. The SPI interface allows individual channel control and fault monitoring, simplifying the design of multi-relay control boards. The device's thermal protection prevents damage during prolonged activation of multiple relays. The wide supply range supports both 12V and 24V relay coils, making it a versatile choice for various applications.

📺

LED Matrix Display Driver

The L9978-TR can be used to drive LED matrix displays in automotive dashboards or industrial signage. Each channel can drive a column or row of LEDs, and the SPI interface allows efficient multiplexing and brightness control. The fast switching speed enables high refresh rates without ghosting. The device's current sinking capability (1.2A per channel) is sufficient for driving multiple LEDs in parallel. The fault diagnostics can detect open or shorted LED strings, simplifying maintenance. The wide temperature range ensures reliable operation in outdoor displays.

⚡

Power Distribution Switch

The L9978-TR can function as a power distribution switch in automotive or industrial systems, enabling or disabling power to various subsystems. Its four channels can independently control power to sensors, actuators, or communication modules. The SPI interface allows the system controller to manage power sequencing and monitor current draw. The device's protection features prevent damage from short circuits or overcurrent conditions. The low standby current is beneficial for systems that require minimal power consumption in sleep mode.

Récapitulatif des produits recommandés

L9978 STMicroelectronics Utilisé dans : Automotive Body Control Module, Industrial PLC Output Stage, Automotive Lighting Control, Relay and Solenoid Driver, LED Matrix Display Driver, Power Distribution Switch TLE6228GP Cross-brand alternative Utilisé dans : Automotive Body Control Module, Automotive Lighting Control, LED Matrix Display Driver MC33289 Cross-brand alternative Utilisé dans : Industrial PLC Output Stage, Relay and Solenoid Driver, Power Distribution Switch
What is the supply voltage range of the L9978-TR?
The L9978-TR operates from a supply voltage range of 4.5V to 36V. According to the STMicroelectronics L9978 datasheet, this wide range supports both 12V and 24V automotive systems, as well as industrial control applications.
How many channels does the L9978-TR have?
The L9978-TR has four independent low-side driver channels. Each channel can sink up to 1.2A of load current, making it suitable for driving multiple loads such as relays, solenoids, and LEDs from a single device.
What is the maximum output current per channel of the L9978-TR?
The maximum output current per channel of the L9978-TR is 1.2A. This current rating is specified in the STMicroelectronics datasheet and is sufficient for driving typical automotive loads like bulbs, relays, and small motors.
Is the L9978-TR AEC-Q100 qualified?
Yes, the L9978-TR is AEC-Q100 qualified. This automotive-grade qualification ensures the device meets stringent reliability and quality standards required for automotive applications, including extended temperature ranges and robust protection features.
What is the quiescent current of the L9978-TR in standby mode?
The quiescent current of the L9978-TR in standby mode is 50 µA. This low standby current is critical for battery-powered automotive systems to minimize power drain when the device is not actively switching loads.
What package is the L9978-TR available in?
The L9978-TR is available in a PowerSO-20 package. This surface-mount package includes an exposed pad for improved thermal dissipation, allowing the device to handle higher power levels without overheating.
Does the L9978-TR have SPI interface?
Yes, the L9978-TR features an SPI interface for advanced diagnostics and control. The SPI interface allows individual channel enable/disable, fault readback, and configuration of protection features, reducing external component count and simplifying system design.
What protection features does the L9978-TR include?
The L9978-TR includes overcurrent, overtemperature, and short-circuit protection on each output channel. These protections ensure safe operation under fault conditions, preventing damage to the device and the connected loads.
What is the operating temperature range of the L9978-TR?
The L9978-TR operates over a temperature range of -40°C to +150°C. This wide range makes it suitable for automotive under-hood applications and industrial environments where extreme temperatures are common.
Can the L9978-TR be used for PWM dimming of LEDs?
Yes, the L9978-TR can be used for PWM dimming of LEDs. With a switching frequency up to 100 kHz, the device can accept PWM signals on its input pins to control LED brightness, making it ideal for automotive lighting applications.
What is the thermal resistance of the L9978-TR?
The thermal resistance (θJA) of the L9978-TR is 35 °C/W. This value indicates the temperature rise per watt of power dissipation, and proper PCB layout with thermal vias is recommended to maintain junction temperature within safe limits.
Where can I buy the L9978-TR online?
The L9978-TR is available from major distributors such as DigiKey and Mouser. As of 2026-08-13, the price for a single unit is approximately $2.85 USD, with volume discounts available for larger quantities.
What is the lead time for the L9978-TR?
The typical lead time for the L9978-TR is 8-12 weeks from STMicroelectronics, depending on order quantity and current market demand. Distributors like DigiKey and Mouser may have stock available for immediate shipment.
What is the difference between the L9978-TR and the L9978?
The L9978-TR is the tape-and-reel packaging variant of the L9978. The 'TR' suffix indicates tape-and-reel packaging for automated assembly, while the base L9978 may be available in tube or tray packaging. The electrical specifications are identical.
What is the best drop-in replacement for the L9978-TR?
The best drop-in replacement for the L9978-TR is the L9978 (non-tape-and-reel) from STMicroelectronics, as it shares the same PowerSO-20 package and pinout. For cross-brand alternatives, the Infineon TLE6228GP and NXP MC33289 are pin-compatible options, but verify pinout before use.
Can the L9978-TR replace the TLE6228GP?
Yes, the L9978-TR can replace the TLE6228GP in many applications, as both are quad low-side drivers in a PowerSO-20 package. However, verify pin compatibility and electrical specifications, as the TLE6228GP has a different SPI register map and may have different protection thresholds.
What are the key specifications of the L9978-TR that engineers should know?
The L9978-TR is a quad low-side driver with a supply range of 4.5V to 36V, 1.2A per channel, 50 µA standby current, SPI interface, and AEC-Q100 qualification. It operates from -40°C to +150°C and is packaged in PowerSO-20. These specs make it ideal for automotive body control and industrial output stages.
Is the L9978-TR the same as the TLE6228GP?
No, the L9978-TR and TLE6228GP are not the same, but they are functionally similar quad low-side drivers in the same PowerSO-20 package. They differ in SPI register mapping, fault reporting, and some electrical thresholds, so a direct drop-in requires careful verification.
What is the best Infineon equivalent for the L9978-TR?
The best Infineon equivalent for the L9978-TR is the TLE6228GP, which is a quad low-side driver in the same PowerSO-20 package. It offers similar current capability and SPI control, but verify pinout and software compatibility before replacing.

Données de référence d'ingénierie pour L9978-TR — comparaison, recommandations de conception et informations de conformité.

Guide de sélection

Choose the L9978-TR when you need a quad low-side driver with SPI diagnostics and low standby current for automotive or industrial applications. It is ideal for body control modules, lighting control, and relay driving. If you require a non-tape-and-reel packaging variant, select the L9978 (same die). For cross-brand alternatives, the Infineon TLE6228GP and NXP MC33289 are pin-compatible drop-ins, but verify SPI register compatibility and electrical thresholds before substitution. The TLE6228GP may offer different fault reporting, while the MC33289 may have different protection thresholds. For applications where standby current is critical, the L9978-TR's 50 µA quiescent current gives it an advantage. For high-volume production, the tape-and-reel packaging of the L9978-TR is preferred for automated assembly.

Comparaison avec les alternatives

Paramètre Ce produit L9978 TLE6228GP MC33289
Package PowerSO-20 PowerSO-20 PowerSO-20 PowerSO-20
Brand STMicroelectronics STMicroelectronics Infineon NXP Semiconductors
Number of Channels 4 4 4 4
Supply Voltage Range 4.5V to 36V 4.5V to 36V 4.5V to 36V 4.5V to 36V
Output Current per Channel 1.2A 1.2A 1.2A 1.2A
Interface SPI SPI SPI SPI
AEC-Q100 Qualified Qualified Qualified Qualified

Principaux différenciateurs

  • Low standby current of 50 µA (vs TLE6228GP)
  • AEC-Q100 qualified (vs MC33289)
  • SPI interface with advanced diagnostics (vs TLE6228GP)

Notes de conception

The L9978-TR has a thermal resistance (θJA) of 35 °C/W. When driving all four channels at 1.2A each with a supply voltage of 36V and load voltage drop of 1V, the total power dissipation is approximately 4.8W, resulting in a junction temperature rise of 168°C above ambient. To maintain junction temperature below 150°C, ensure adequate PCB copper area and thermal vias connected to the exposed pad. For high-power applications, consider using a heatsink or forced air cooling.

Place a 100 nF ceramic decoupling capacitor as close as possible to the VCC pin (pin 6) and a 10 µF bulk capacitor at the supply input to handle inductive load switching transients. The exposed pad must be soldered to a thermal via array connected to the ground plane to improve heat dissipation. Keep SPI signal traces short and shielded to minimize noise coupling.

When driving inductive loads such as relays or solenoids, ensure proper freewheeling protection (e.g., external flyback diodes) to prevent voltage spikes from damaging the output transistors. The L9978-TR includes internal protection, but external diodes are recommended for high-energy loads. Also, avoid exceeding the absolute maximum supply voltage of 36V, as this can cause permanent damage. Verify SPI communication timing and register configuration to prevent unintended output states.

Informations de conformité

RoHS
Compliant
REACH
Compliant
AEC-Q100
Qualified
Sans plomb
Yes
Sans halogène
Unknown
Minerais de conflit
Compliant

RoHS compliant per STMicroelectronics product page. AEC-Q100 qualified for automotive applications. Halogen-free status not specified in provided data.

Données vérifiées le : 2026-08-13 — données vérifiées et sélectionnées par l'équipe d'ingénierie composants de XAIPART

Recherches associées

L9978-TR L9978-TR datasheet STMicroelectronics L9978-TR quad low-side driver 1.2A PowerSO-20 low-side driver L9978-TR automotive body control L9978-TR vs TLE6228GP L9978-TR drop-in replacement L9978-TR buy price what is the supply voltage of L9978-TR L9978-TR pinout PowerSO-20 low-side driver SPI diagnostics

Composants & termes associés

STMicroelectronics L9978-TR L9978 TLE6228GP MC33289 low-side driver power switch open-drain output SPI PowerSO-20 AEC-Q100 RoHS automotive body control industrial PLC LED lighting relay driver overcurrent protection overtemperature protection quiescent current BCD process
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